Question: What is population of Ostrava that is point in time is 2017-1-1?
Paraphrase: How many people live in Ostrava as of 2017-1-1?
SPARQL (Wikidata): SELECT ?obj WHERE { wd:Q8385 p:P1082 ?s . ?s ps:P1082 ?obj . ?s pq:P585 ?x filter(contains(YEAR(?x),'2017')) }